Drought coverage and intensity remained nearly steady across the West with more than two-thirds of California designated with extreme to exceptional drought. Drought intensified during the past month across the central and southern Great Plains, while the Midwest experienced drought reduction. Most of the eastern U.S. remains drought-free. The drought outlook valid through July 31, 2014 is based primarily on initial conditions, short-, medium-, and long-range forecasts, and climatology. Persistence or intensification is likely for the ongoing drought areas of the Pacific Northwest, California, and Great Basin as those areas enter an increasingly dry time of year. Also, the Climate Prediction Center (CPC) seasonal outlook calls for enhanced odds for above-normal temperatures across the West. Persistence is forecast for much of the Southwest, although improvement/removal is forecast for western New Mexico as the CPC May-June-July outlook calls for increased chances of above-median precipitation. Improvement is not expected to occur until July with the onset of monsoon rainfall. Improvement and removal of drought across the central/southern Great Plains and Midwest is based on expected rainfall during the remainder of April and a relatively wet time of year as the convective season peaks. However, persistence is most likely for the protracted drought areas of the high Plains. Although drought is not expected to develop through the end of July along and east of the Mississippi River, summer heat coupled with insufficient rainfall over a multi-week period can result in rapid drought development during the summer.
Long-term drought is predicted to continue across California, interior Oregon, the Great Basin, the Desert Southwest, the southern Rockies, and the southern High Plains, as the traditional winter wet season draws to a close in the next few weeks. Mountain snow packs are running well below-average across much of this region. The Pacific Northwest still has a while yet before entering their climatological dry season, so there are opportunities for drought improvement and removal there.
Across the central portion of the contiguous United States, drought improvement and/or removal is anticipated over the lower central and southern Great Plains and Upper and Middle Mississippi Valley.
However, farther west across the High Plains, the odds for improvement or removal are not as good, prompting persistence of drought conditions.
According to NOAA’s Spring Outlook recently, rivers in half of the continental United States are at minor or moderate risk of exceeding flood levels this spring with the highest threat in the southern Great Lakes region due to above-average snowpack and a deep layer of frozen ground.
Additionally, drought is expected to continue in California and the Southwest.
Much needed precipitation brought limited drought relief to parts of the Northwest, the Great Basin, and the northern Intermountain West, but drought continued to expand and intensify across parts of California, the desert Southwest and the southern Rockies. Outside of spotty precipitation over southern and western Texas, drought also expanded across much of the central and southern Plains, and short term drought developed along the western GulfCoast. Widespread precipitation brought drought relief to the eastern U.S. Drought persistence and expansion are anticipated for California, the Southwest, and the southern Plains due to dry initial conditions heading into the climatologically drier Spring season. CPC 1-Month and 3-Month outlooks tilt the odds towards below-median precipitation over parts of the Southwest and California as well. In contrast, short range forecasts for heavy precipitation increase prospects for additional drought relief across the Pacific Northwest and the northern Rockies, although anticipated warmer than normal temperatures may limit effective snow pack building for late spring water resources. Drought improvement or removal is forecast for the central Plains and the middle and upper MississippiValley, where climatological precipitation increases substantially during April and May. While locally heavy precipitation is forecast in the short term for parts of the central and western Gulf Coast, which would ease short term drought conditions, the CPC seasonal outlook indicates enhanced chances of below-median rainfall. With 90-day precipitation totals generally below 75 percent of normal, it is possible for short term drought reductions to be offset by redevelopment later in the Spring.
During the past month, drought conditions improved across parts of the Intermountain West, Rockies, southern Plains, lower Mississippi Valley, upper Midwest, mid-Atlantic, and Northeast. In most of these areas, the trend toward improvement is not expected to continue through the first 3 months of 2014, and in fact some drought development (or re-development) is anticipated in portions of the central and southern Rockies and the Southwest. Drought is expected to be a continuing or worsening concern along the West Coast and in the Southeast.
A large storm system in the 7 days before Christmas should bring 1 to several inches of precipitation from the southern High Plains northeastward through parts of the Midwest and the Northeast, setting the stage for drought improvement or removal in the scattered areas of drought across eastern Texas, eastern Missouri, central Illinois, and the Northeast. In addition to effects from this system, surface moisture – whether in soils and water sources or locked up in snowpack – usually increases in these regions during January – March.
Improvement is also expected in central Idaho and adjacent areas, where the January outlook favors above-normal precipitation after relatively dry weather through the end of December. Elsewhere, the trend toward decreasing drought should continue in Alaska, and with odds significantly favoring above-normal rainfall in Hawaii for January and January – March, continued slow improvement is anticipated there.
In contrast, below-normal precipitation seems more likely for January – March in the Southeast and much of the southwestern quarter of the country. Drought is expected to persist where it exists in these regions, and expand to cover areas currently exhibiting some degree of dryness (generally areas shown as abnormally dry, or D0, in the Drought Monitor). This includes Florida and a swath from the Carolinas to the central Gulf Coast in the Southeast, and most areas not already experiencing drought from Colorado and eastern Utah southward through the desert Southwest and southern Rockies, along with westernmost Texas.
California and adjacent areas in the Far West will be closely monitored this period. Patches of above-normal precipitation have been analyzed in southeastern California, but most of the state received less than half of normal precipitation during the last half of 2013, as did parts of adjacent Oregon and Nevada. From southern sections of California’s central valley to the coastal strip between San Francisco and Los Angeles, many locations recorded less than 25% of normal precipitation since late June. Both the January and January – March precipitation outlooks indicate enhanced chances for below-normal precipitation across much of the state and neighboring areas, thus drought is expected to persist or intensify.
Winter is likely to offer little relief to the drought-stricken U.S. Southwest, and drought is likely to develop across parts of the Southeast as below-average precipitation is favored in these areas of the country, according to NOAA’s annual Winter Outlook recently announced.
The November 2013 Drought Outlook is based on initial conditions, short and medium range forecasts, updated monthly outlooks for temperature and precipitation, and climatology.
During late October, heavy rains ahead of a slow moving cold front fell across parts of south-central and southeastern Texas, causing localized flooding in Austin and regions just to the southwest. Widespread rainfall associated with the same storm system also overspread eastern Kansas, Missouri, southern Iowa, and northern Illinois, with accumulations of an inch or greater observed. Additional rainfall in these areas are expected during the first week of November, as ridging builds over the Southeast, promoting slow frontal passages as new mid-latitude storms develop across the Mississippi Valley. Therefore, drought improvement or removal is anticipated across south central and eastern Texas and along the middle and lower Mississippi Valley.
Further east, the ridging over the Southeast is forecast to prevent significant rainfall from reaching the Atlantic coast. Drought development is possible across parts of the Southeast, especially along the Savannah River basin, where 30-day percent of normal precipitation values are particularly low. Drought has also expanded across parts of the Northeast, and without a clear signal for wetness during the first half of November, persistence is anticipated. Uncertainty increases towards the end of the month, as coastal winter storms become more likely.
November is a climatologically dry time of year across the Plains and intermountain West, making drought persistence most probable.
Winter storm activity increases across the Pacific Northwest during late autumn, but sufficient precipitation to overcome current drought conditions is not likely to occur until later in the winter season, especially across California.
During the previous 30 days, below average rainfall was observed along most of the eastern seaboard and the Appalachians, promoting the expansion of abnormal dryness across the Northeast and parts of the southern Atlantic coastal plain. In contrast, several days of heavy rainfall over the Chesapeake watershed associated with a slow moving coastal storm caused localized flooding. Heavy rainfall also fell across much of Texas, the lower Mississippi Valley, and the Ohio Valley, resulting in drought improvement. Wet weather across the northwestern quadrant of the continental U.S. contrasted with mostly dry weather over the Southwest.
Additional short term drought improvement is possible for eastern and central Texas as a slow moving front brings additional widespread rainfall, although an anticipated seasonal tilt towards abnormal dryness supports drought persistence over the remainder of the Southern Plains.
Drought development is possible across much of the Southwest, while seasonable winter wetness may bring some relief to coastal California and the northern Rockies. Late fall and winter is climatologically dry across the Plains and Midwest, making significant improvements of lingering drought less likely. Incipient dryness across parts of the southern Atlantic coastal plain and enhanced chances of below median precipitation during the November through January period raise the potential for drought development.
NOAA recently issued its updated Atlantic hurricane season outlook saying the season is shaping up to be above normal with the possibility that it could be very active. The season has already produced four named storms, with the peak of the season – mid-August through October – yet to come.
According to NOAA scientists, the average temperature for the contiguous United States during March 2013 was 40.8°F, 0.9°F below the 20th century average.
It was the 43rd coolest March on record. Colder temperatures dominated east of the Rockies, and warm conditions prevailed in the West.